It’s easy to blame fate on losing the game. And maybe that is WHY you lost the game. But if you want to improve then you have to look at the cards dealt to you with a lense of finding the best play available. This is all well and good because sometimes it is difficult during the pressure of the game to always choose the optimally best decision at the time: time and the awesome amount of information at your hand coupled with the infinite amount of decisions that are possible can make this process difficult even with unlimited amounts of time. So how does one improve?
Well, the most obvious answer is practice, practice, practice.
The second answer is perhaps not as obvious but certainly not revolutionary. Keep notes of your games. Reflect on decisions you made in the games and try to recreate the game state at that time. A good example of this was when I was playing NBN. I had advanced four points worth of agendas. One of them was an Astroscript Pilot with a hosted counter still in place. I was playing against Kate so my R&D was vulnerable and a likely target. My move was to install another astroscipt and then get an agenda for the win after that. When I advanced to 6 agenda points and I had another Astroscript hosted counter ready to advance any likely agendas that came my way. This seemed like good strategy at the time but my opponent used an Indexing, ran my R&D twice for the win.
Shitty luck, right?
Well yes and no.
I made my opponent win in this case. Reviewing the game afterwards allowed me to see that I limited my opponents choices to one! He had to run R&D. On reflection, I should have held onto my agenda until I drew a piece of icebreaker capable of protecting R&D adequately OR drew another solution entirely.
This reflective process makes my game better because I am prepared for future challenges and have thought through how to deal with them. Chris Hadfield, Canadian astronaut, would call this sweating the small stuff. So, sweat the small stuff Netrunners, sweat away so that you can live to run or corp another day!